And he that wole han pris of his gentrye,
For he was boren of a gentil hous
And hadde his eldres noble and vertuous,
And nel hymselven do no gentil dedis
Ne folwen his gentil auncestre that deed is,
He nys nat gentil, be he duc or erl,
For vileyns synful dedes make a cherl.

– Geoffrey Chaucer

The Canterbury Tales, The Wife of Bath’s Tale. A person is not noble who is born into a noble house and doesn’t himself do noble deeds, even if he is a duke or earl. So says the Knight’s hag wife. Villainous sinful deeds make him a churl, a peasant of low status, she adds in an obvious reference to her husband’s crime of rape.